镍铁水滑石/还原氧化石墨烯的制备及电催化水氧化性能

首先制备了不同镍/铁比的镍铁水滑石,并通过液相剥离法得到水滑石纳米薄片溶胶,随后将其与还原氧化石墨烯复合,并对其进行了电催化水氧化的性能测试.结果表明,镍铁水滑石的剥离可以大幅度提高其电催化性能,起峰电位为1.47V,电流密度为10mA/cm^2时,电位仅为1.53V;与还原氧化石墨烯复合后,其催化活性得到了进一步提高,在10mA/cm^2时电位降为1.515V.

核潜艇舱室一体化空气再生系统技术设想

本文提出一种核潜艇电催化制氧耦合二氧化碳消除空气再生系统技术设想,该系统以膜电极构型电解反应器为核心,电解反应器中阳极进行水氧化反应制氧,阴极则将二氧化碳电催化还原为甲酸、甲醇等液体产物,实现核潜艇舱室供氧和二氧化碳消除一体化耦合。该系统只需常温常压条件下运行,运行过程中不产生氢气等危险气体副产物,产生的甲酸、甲醇等液体产物易于排放,能够联合集成二氧化碳吸收装置,且无需配套压缩机组。该设计能够改进和提高舱室空气再生系统使用性、安全性和潜艇隐蔽性,进一步提升核潜艇作战能力。

Preparation and application of perovskite-type oxides for electrocatalysis in oxygen/air electrodes

Recent advances in the preparation and application of perovskite-type oxides as bifunctional electrocatalysts for oxygen reaction and oxygen evolution reaction in rechargeable metal-air batteries are presented in this review.Various fabrication methods of these oxides are introduced in detail,and their advantages and disadvantages are analyzed.Different preparation methods adopted have great influence on the morphologies and physicochemical properties of perovskite-type oxides.As a bifunctional electrocatalyst,perovskite-type oxides are widely used in rechargeable metal-air batteries.The relationship between the preparation methods and the performances of oxygen/air electrodes are summarized.This work is concentrated on the structural stability,the phase compositions,and catalytic performance of perovskite-type oxides in oxygen/air electrodes.The main problems existing in the practical application of perovskite-type oxides as bifunctional electrocatalysts are pointed out and possible research directions in the future are recommended.

Preparation and application of electro-catalytic material Fe_2O_3-ZnO/C

Electro-catalysts Fe203 compounded by ZnO were prepared by a sol-gel method, which were titled as Fe203-ZnO. Electro-catalysts Fe203-ZnO loading on the bamboo charcoal was titled as Fe203-ZnO/C. The catalytic materials were characterized by X-ray diffraction （XRD） and scanning electron microscope （SEM）. The obtained catalysts were assembled to three-dimensional electrodes to degradation of chlorinated organic in paper wastewater. And the performance tests show that three-dimensional electrodes have high activities for degradation of chlorinated organic in paper wastewater. There are many factors affecting the electro-catalytic performances of the three-dimensional electrodes. And the orthogonal experiment results show that the optimum operating condition is as follows： the calcination time of the catalysts 2 h, the mass ratio of Fe to Zn 4：1, the voltage 12 V, the mass of the catalytic materials 6 g, the value of pH 9, and the treating time 2.5 h. Under these conditions, the optimum removal efficiency of chlorinated organics in paper wastewater is 47.58%.

Oxygen Electroreduction Performance of Ultrasmall Gold Nanoclusters

Ultrasmall gold nanoclusters consisting of 2-4 Au atoms were synthesized and their per- formance in electrocatalytic oxygen reduction reactions （ORR） was examined. These clus- ters were synthesized by exposing AuPPh3Cl to the aqueous ammonia medium for one week. Electrospray ionization mass spectrometry （ESI-MS）, X-ray absorption fihe struc- ture （XAFS）, and X-ray photoelectron spectroscopy （XPS） analyses indicate that the as- synthesized gold clusters （abbreviated as Aux） consist of 2-4 Au atoms coordinated by the triphenylphosphine, hydroxyl, and adsorbed oxygen ligands. A glassy carbon disk electrode loaded with the Aux clusters （Aux/GC） was characterized by the cyclic and linear-sweep voltammetry for ORR. The cyclic voltammogram vs. RHE shows the onset potential of 0.87 V, and the kinetic parameters of JK at 0.47 V and the electron-transfer mmlber per oxygen molecule were calculated to be 14.28 mA/cm2 and 3.96 via the Koutecky-Levich equations, respectively.

Two-dimensional titanium carbide MXenes as efficient non-noble metal electrocatalysts for oxygen reduction reaction

MXenes, a new family of multifunctional two dimensional(2D) solid crystals integrating high electroconductivity and rich surface chemistries, are promising candidates for electrolysis, which, however, have rarely been reported. Herein, free-standing ultrathin 2D MXene nanosheets were successfully fabricated from bulky and rigid MAX phase ceramics by liquid exfoliation with HF etching(delamination) and TPAOH intercalation(disintegration).The high oxygen reduction reaction(ORR) performance has been obtained, due to the extremely small thickness of the asfabricated Ti3C2 around 0.5–2.0 nm, equivalent to the dimensions of single-layer or double-layer Ti3C2 nanosheets in thickness. The ORR performance of the obtained Ti3C2 MXene-based catalyst exhibits desirable activity and stability in alkaline media. This study demonstrates the potential of earth-abundant 2D MXenes for constructing high-performance and cost-effective electrocatalysts.

3D ordered mesoporous cobalt ferrite phosphides for overall water splitting

Developing low-cost and earth-abundant electrocatalysts with high performance for electrochemical water splitting is a challenging issue. Herein, we report a facile and effective way to fabricate three-dimension(3D) ordered mesoporous Co1-xFexP(x=0, 0.25, 0.5, 0.75) electrocatalyst.Benefiting from 3D ordered mesoporous pore channels and composition optimization, the Co0.75Fe0.25 P exhibits excellent electrocatalytic activities with low overpotentials of 270 and 209 mV at 10 mA cm^-2 for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER), respectively, in the alkaline electrolyte along with a durable electrochemical stability. In addition, as both the cathode and anode, the Co0.75Fe0.25P also exhibits superior electrolysis water splitting performance with only an applied voltage of 1.63 V to attain a current density of 10 m A cm^-2 without obvious decay for 18 h,indicating that the Co0.75Fe0.25P is an efficient electrocatalyst for overall water splitting.

Shape-controlled Pt nanocubes directly grown on carbon supports and their electrocatalytic activity toward methanol oxidation

Synthesis of shape-controlled Pt nanocrystals is substantial and important for enhancing chemical and electrochemical reactions.However,the removal of capping agents,shape-controlling chemicals,on Pt surfaces is essential prior to conducting the catalytic reactions.Here we report a facile one-pot synthesis of Pt nanocubes directly grown on carbon supports(Pt nanocubes/C) with modulating the kinetic reaction factors for shaping the nanocrystals,but without adding any capping agents for preserving the clean Pt surfaces.Well-dispersed Pt nanocubes/C shows enhanced activity and long-term stability toward methanol oxidation reaction compared to the commercial Pt/C catalyst.

Decoupling hydrogen production from water oxidation by integrating a triphase interfacial bioelectrochemical cascade reaction

Water electrolysis to produce H2 is a promising strategy for generating a renewable fuel.However,the sluggish-kinetics and low value-added anodic oxygen evolution reaction(OER)restricts the overall energy conversion efficiency.Herein we report a strategy of boosting H_(2)production at low voltages by replacing OER with a bioelectrochemical cascade reaction at a triphase bioanode.In the presence of oxygen,oxidase enzymes can convert biomass into valuable products,and concurrently generate H_(2)O_(2) that can be further electrooxidized at the bioanode.Benefiting from the efficient oxidase kinetics at an oxygen-rich triphase bioanode and the more favorable thermodynamics of H_(2)O_(2)oxidation than that of OER,the cell voltage and energy consumption are reduced by~0.70 V and~36%,respectively,relative to regular water electrolysis.This leads to an efficient H_(2)production at the cathode and valuable product generation at the bioanode.Integration of a bioelectrochemical cascade into the water splitting process provides an energy-efficient and promising pathway for achieving a renewable fuel.